• Preheat the oven to 375F/190C. You will need a 9 x 9in (23 x 23cm) square baking pan/tin - ideally non-stick, otherwise you may want to line it with parchment paper. I use a 2in (5cm) deep pan, but slightly less deep will also work.

For pastry base

• Place the flour, confectioners/icing sugar and butter in a food processor and pulse to form crumbs. Add the water in a steady stream with the food processor running. Blend to bring the mixture together in clumps - if it doesn't happen after around 30 seconds, add a little more water but you shouldn't need much more.
• Remove the dough from the food processor and press together to form a ball. Roll out into a large square, large enough to line a 9 x 9in (23 x 23cm) baking tin. Carefully place the pastry into the tin and gently press into the corners and up the side.
• Trim the top off the pastry to give an even edge a little below the top of the tin. If the pastry is lower in any area, you can add a bit of the cut off scraps to fill it in, pressing to join to the main pastry. Prick the base of the pastry all over with a fork then chill in the fridge a few minutes - ideally 10 or more - while the oven heats up.
• Blind bake the pastry (ie line inside with parchment and fill with baking beans) for about 10 minutes, then remove parchment and beans and bake uncovered for around 5 - 10 minutes more until lightly golden.

For sponge topping

• Meanwhile, place the butter, flour, almond flour, sugar, baking powder, almond extract and eggs in a bowl. Mix with a stand or handheld electric mixer to combine well and until the mixture os smooth and glossy.

To layer and bake

• Once the pastry is gently golden and dry, spread a layer of the raspberry jam over the pastry base, spreading right into the corners and trying to make an even layer.
• Dot the almond sponge topping mixture over the jam so it covers most of the jam (it doesn't have to be smooth at this point, you just want to minimize how much you need to spread it). Carefully spread the sponge layer over the jam, trying not to touch the jam so that you don't mix it into the topping. Spread right to the very edges to touch the pastry sides and smooth the top with a spatula.
• Sprinkle the almonds evenly over the top, then bake for around 35 - 40 minutes until the top is evenly golden and dry to touch.
• Allow to cool at least a few minutes before slicing - you can serve warm or at room temperature.
• If storing, allow to cool completely to room temperature before transferring to a sealed container and storing at room temperature.